For a company known for its secrecy, a lot of details about Apple’s rumored smartwatch are leaking. The latest: The tech giant is planning to release multiple versions of its smartwatch with different screen sizes for a launch this fall, according to The Wall Street Journal.

Citing people familiar with the matter, the Journal says the smartwatch will include at least 10 sensors, including ones that monitor fitness and health. Apple is said to have tapped Taiwanese company Quanta Computer to manufacture the device, with trial runs taking place in July.

Earlier reports suggest that Apple’s so-called iWatch team includes about 100 product designers, including managers, marketers, and engineers who previously worked on the iPad and iPhone. The company could also introduce a new way to charge the hardware, such as magnetic induction, solar power, and movement.

Samsung beat Apple to the punch by introducing the Galaxy Gear in the fall, and has since released three more smartwatch models. Last month, the company introduced a new platform for health and fitness monitors and also showed off Simband, a prototype device that can track heart rate, oxygen levels, temperature, and other metrics in real time.

One week later, at the Worldwide Developer Conference, Apple highlighted its health platform Healthkit in the upcoming iOS 8 operating system. Similar to Samsung’s platform, Healthkit will act as a centralized hub for third-party apps–measuring, storing, and consolidating information that would otherwise be siloed off, to derive health insights for consumers.